A composition for reducing dentinal hypersensitivity and remineralizing exposed dentinal surface and open dentinal tubules, comprising a non-aqueous carrier and a desensitizing amount of a desensitizing/remineralizing agent which consists essentially of a water soluble calcium salt and an incompatible ingredient which would otherwise react with the calcium salt. Upon contact with saliva when applied to an oral cavity, the desensitizing/remineralizing is then formed in situ by the reaction between the calcium salt and the incompatible ingredient, thereby remineralizing exposed dentinal surface and open dentinal tubules.